CARDIOPROTECTIVE EFFECTS OF ADAPTATION TO RESTRAINT STRESSES AND HYPOXIA

Isolated rat heart experiments have revealed that restraint stress ada ptation results in enhanced resistance of the isolated heart to reperf usion. There is also a higher resistance to the autolysis of the organ elles isolated from the hearts of stress-adapted animals. This complex of changes is designated as a phenomenon of adaptive stabilization of structures (PhASS). The phenomenon developing in restraint stress ada ptation substantially limits arrhythmias, contracture, contraction amp litude depression, and creatine kinase release into the perfusate in t hermal damage to the isolated rat heart. Simultaneously, PhASS is acco mpanied by a multiple increase in five hsp70 isoforms with pI 5.8-6.3 in cytosole and two isoforms with pI about 6.3 in the nucleoplasm. Onl y two hsp70 isoforms with pl about 5.8 accumulate solely in cytosole d uring adaptation to intermittent hypoxia. Consistently, the resistance of Ca2+-pump. and nuclear DNA remains unchanged and the protection ag ainst reperfusion and thermal damage are several times less pronounced .